1. Field of the Invention
This invention relates in general to security devices, and, more particularly, to a method and an apparatus for detecting unauthorized disturbance of a protected surface.
2. Description of the Related Art
Maintaining the security of circuitry and devices from unauthorized tampering is a difficult problem in today's industrial environment. The purpose of such tampering might be to reverse-engineer, sabotage, or access the contents of a container or tap into circuitry.
Currently, any product which requires that its contents remain secure from unauthorized penetration has a limited number of security devices available for its protection. Examples of such sensitive devices are TEMPEST electronic devices and secured data communication links carrying such sensitive data as financial transactions or personal communications.
In general, the known existing state of the art appears in the form of a product having insulated wires woven into a screen mesh. The woven wires are monitored for a break which in turn sounds an alarm. However, in this product the weave pattern is highly repetitive due to its automated manufacturing process, and due to structural and cost considerations, only a small number of active sensing wires are woven into the overall mesh. With this configuration of both a highly repetitive pattern and sparse sensing wires, it is fairly easy to overcome and penetrate the device in an undetected manner.
Such existing protection devices are also complicated, bulky, contain less sensing elements, are of dubious reliability and therefore are easily circumvented.